Static vane airfoils and other turbine parts may incorporate a cooling circuit which passes coolant, typically compressor bleed air, through the surface of the airfoil and into the turbine gas path. The amount of compressor bleed air passed through a part is typically determined by that part's hottest running condition to ensure that the part will survive that condition. For a typical operating cycle, a part spends little time at its maximum operating temperature. Thus, for the majority of its operating time, more compressor bleed air than is needed may be flowed through the part. Engine efficiency typically decreases as compressor bleed air through a part increases.